In piezoelectric inkjet printheads, ink or other fluid is typically ejected in the form of drops. The fluid travels from various fluid chambers, through various nozzles, onto a substrate. The fluid is ejected by movement of a piezoelectric element. The fluid chamber has a wall that consists of a piezoelectric actuator, typically a membrane that is connected to the piezoelectric element. The fluid is moved towards the nozzle by vibration movement of the membrane actuated by the piezoelectric element.
At present, piezoelectric actuators of the unimorph type comprise a flexible membrane that is integrated with or attached to a piezoelectric layer. When the actuator has a relatively small thickness, e.g. between 1 and 10 micron, such as with thin film piezoceramic and thin membrane layers, the maximum width it may span over the fluid chamber is usually at most between 50-100 micron or less. At larger spans, the actuator is unsuitable to achieve a desired frequency and/or pressure. Therefore, the fluid chamber usually has an elongate shape, so that the maximum width is between about 50-100 micron or less, while its length is significantly larger, e.g. between 0.5 mm-2 mm.
It is an object of the invention to provide for an alternative piezoelectric method and device.